Two men who once knew each other in middle school reunite as young adults and vow to earn one trillion dollars from scratch. This is the starting point of a story told in flashback from the perspective of Gaku, who in the present day sits atop a global empire, reflecting on the unlikely journey that got him there. The narrative chronicles the rise of Trillion Game Inc., a startup built on an almost absurdly ambitious goal by two polar opposites.

The first is Haru, a self-proclaimed "world's most selfish man" gifted with boundless charisma, sharp intelligence, and an almost supernatural ability to persuade anyone of anything. He is the face and the force behind the operation, a risk-taker who sees rules as suggestions and obstacles as opportunities. The second is Gaku, a reclusive and socially anxious computer programming prodigy whose technical genius is matched only by his lack of communication skills. Together, they form an unlikely but devastatingly effective partnership: Haru dreams up the impossible and talks their way into any room, while Gaku quietly builds the technology that turns those dreams into reality.

Their journey begins in the shadow of Dragon Bank, a monolithic IT conglomerate that dominates the Japanese business landscape. After Gaku is rejected for a job at the bank despite his obvious talents, Haru, who had been hired, quits on the spot. Rejecting the safety of corporate life, they decide to build their own company from nothing. Their early ventures are a series of high-wire acts, from blustering their way into a high-stakes hackathon to secure initial funding, to creating a fake AI personality to run an online flower shop. Each scheme relies on Haru's audacious bluffs and Gaku's ability to deliver a technical solution at the last possible second.

The duo quickly attracts rivals and allies. Their primary antagonist is Kirika, the brilliant and arrogant board director of Dragon Bank, who becomes obsessed with bringing the pair under her control. Their first major investor is Kazuki, a foul-mouthed venture capitalist in a cowboy hat who sees past their rough exterior. As Trillion Game grows, the team expands to include Rinrin, a rigid but detail-oriented college student who becomes the company's president, and Shingo, a passionate but struggling game designer whose small studio they acquire. A major arc involves challenging Dragon Bank's dominance in the social gaming market, forcing the upstarts to innovate rapidly and recruit a cynical gacha game designer from their rival's own ranks to create a hit title.

The live-action series is set in contemporary Japan, contrasting the polished, sterile offices of corporate giants like Dragon Bank with the chaotic, energetic workspaces of a startup operating out of borrowed rooms and sheer will. The show moves at a rapid pace, following Haru and Gaku as they pivot from one bold idea to the next: launching an online media outlet, navigating hostile takeover attempts, and executing elaborate schemes to outmaneuver larger, more established competitors. At its core is the symbiotic relationship between Haru and Gaku, whose friendship and mutual reliance are tested but never broken as they hustle their way from penniless outsiders to the brink of an unimaginable fortune.